This invention relates generally to the field of devices used to contain liquids, and especially such devices used as secondary containment to capture spills or run-offs of hazardous or non-environmentally-friendly liquids. More particularly, the invention relates to such devices which comprise a unified bottom and side walls to define a relatively large volume reservoir. Even more particularly, the invention relates to such devices which provide means to enable a wheeled vehicle to be driven into and out of the device, where at least a portion of the wall is collapsible as a wheel crosses and which rebounds once the wheel has passed.
There are numerous circumstances where it is desirable or required by law to contain certain hazardous liquids to prevent the liquids from entering the environment. For example, any spillage of liquids such as gasoline, oil, detergents, chemicals or the like during loading and unloading operations between liquid transport vehicles and storage tanks, during vehicle clean-up operations, or during vehicle fueling, must be captured and properly disposed of. Most locations where these events occur have no permanent recapture structures or systems, so it is necessary to provide a walled containment apparatus which is sufficient in size to allow a vehicle, such as a large tanker truck, to be positioned within its walls. Means to allow the vehicle to enter and exit the containment apparatus must also be provided. In general, apparati of this nature comprise pool-like structures, and typically are either fully rigid, have flexible walls of sheet material and gate means, have flexible walls and compressible wall support means, or have flexible walls and deformable or collapsible wall support means.
For example, U.S. Pat. No. 5,478,625 to Wright, shows a rigid containment device. Double-sided ramps at each end of the device enable a vehicle to be driven into and out of the device. U.S. Pat. No. 5,547,312 to Schmitz, Jr., shows a pool-like apparatus having a floor and side walls made of a flexible sheet material. The walls are supported by a rigid frame having a peripheral upper member and a gate is provided at one end which can be lowered and raised to provide entry and exit means for the vehicle. U.S. Pat. No. 5,464,492 to Gregory et al. shows a containment device with walls supported by a foam member which is compressed by the vehicle wheel and which rebounds to create the wall when the vehicle wheel has passed. U.S. Pat. No. 5,090,588 to Van Romer et al. shows a device made of a flexible sheet material, where the wall is supported by a combination of vertical members adjacent the wall, a peripheral upper member, and internal brace members mounted to the floor of the device. The vertical support members and wall flex when a wheel passes over, and the internal brace members pull the wall back into the upright position after the wheel has passed.
It is an object of this invention to provide an improved liquid containment apparatus for capturing liquid spills, especially such an apparatus where a wheeled vehicle can be driven into and out of the containment apparatus. It is a further object to provide such an apparatus which is composed of flexible, liquid-impermeable, sheet material joined to create a floor and side wall, where said side wall is supported by a number of spaced, collapsible, support members with no need for a peripheral upper member, such that the apparatus is readily collapsible for transport or storage. It is a further object to provide such an apparatus where the wall support members have a relatively rigid upper member hingedly attached to a base member horizontally disposed beneath the floor whereby the upper member can flex either inwardly or outwardly, and where the upper member is slanted inward relative to the interior of the device when in the passive position, preferably at an angle of about 10 degrees from vertical, and further where the hinge member is sufficiently stiff to prevent outward flexation except when a vehicle wheel crosses the side wall. These and other objects are accomplished as set forth below.